Opening device on bags and the like



June 23, 1970 R. L. DREYFUS ET AL 3,516,537

OPENING DEVICE ON BAGS AND THE LIKE Filed June 27, 1968 2 Sheets-Sheet lI INVENTORS ROBERT 1.. DREYFUS WILLIAM o. GRIFFITHS STANLEY E. 'HOLBROOKRICHARD R. PERDUE WILLIAM Z. SNOW June 23, 1970 R. L. DREYFUS ET AL3,516,537

OPENING DEVICE ON BAGS AND THE LIKE Filed June 27, 1968 V Sheets-SheetFIG. 7

IN VE N TORS ATTORNEY United States Patent US. Cl. 206-46 16 ClaimsABSTRACT OF THE DISCLOSURE A package in which an object is encased inplastic and the plastic has a unitary part formed into a tab external ofthe packages enclosure that cooperates with a seal to strip an openingin the package along the seal and a bag suitable for forming such apackage.

The present invention relates to a new and improved package having wallsconstructed so that a unitary portion of the material of the walls formsan easy opening structure for the package and to a new and improved bagconstructed to form the walls of the package and provide the easyopening structure.

While the opening of packages of the general type described is a problemthat needs improving, a special problem is presented in opening packagesthat are formed by loading an item such as a turkey into a bag andthereafter vacuumizing the bag, gathering and clipping the neck, andthen shrinking the bag. Even if the clip is later removed the neck oropening into the bag will generally not open back out large enough toallow the turkey or other item to be removed from the bag. This is, ofcourse, because the total dimensions of the bag have reduced due toshrinking, particularly in those areas where the shrinking was notrestrained by the turkeys bulk. Thus the opening of such a packagepresents special problems. These problems are increased when the bag ismade from a material that resists tear initiation.

It is an object of this invention to provide an easy opening package.

It is a more specific object of this invention to provide an improvedpackage that has as a unitary part of its walls a structure enabling theeasy opening of the package.

It is another object of this invention to provide such a package thatcan be easily and economically fabricated from plastic film.

It is a still further object of this invention to provide such anopening structure that will cause a wide opening to be formed in thepackage without the use of aids evternal of the packages walls.

It is another object of this invention to provide a new and improved baghaving an easy opening device unitary with the walls of the bag.

It is a still further object of this invention to provide such a bagthat has a simple structural design and is easy and inexpensive tomanufacture.

It is a further object of this invention to provide such a bag that willlend itself readily to the construction of a package having thepreviously described features.

It is a further object of this invention to provide a bag and a packagethat readily lend themselves to the packaging of perishable food stuffssuch as turkeys and ring bologna in automated and semi-automated packinglines in a simple and inexpensive manner requiring relatively unskilledlabor and producing a package that is easy for the housewife to open.

In summary, carrying out our invention in one form thereof, a package isprovided having plastic walls that 3,516,537 Patented June 23,, 1970form an enclosure. The enclosure has a closure at at least one locationwhere the enclosing walls are attached or sealed together. As usedherein the several walls of the package may be made from one continuoussheet of plastic film. A portion of the plastic walls extends beyond theclosure and is formed into a tab suitable for gripping to tear throughthe closure into the enclosure.

By an aspect of this invention the closure is a thickened region of thepackage and bounds the enclosure in one region. The entrance edge of thetab is directed so that it tears at a right angle to the outside edge ofthe closure to secure entrance into the closure. The thickened region ofthe closure is rendered stronger than the separate walls of theenclosure and thus serves as a tear strip to enlarge the breach into thepackage along the configuration in which it lies.

By still further aspect of this invention, the package is of shrunkoriented thermoplastic material and maintains a firm pressure on anobject enclosed within its walls. A skirt of two walls extends along theclosure outside of the enclosure. The skirt is shrunk to increase thethickness of its walls and strengthen the tear strip feature of theclosure. A sector of the skirt constitutes the tab sector and this tabsector has a notch entering therein at a right angle to the closureseal. The notch divides the tab sector into a tab and a nub. The shrinkof the tab in the direction parallel to the closure line not onlythickens the skirt, it is also active in engaging the tab against theoutside of the enclosure and in maintaining the tab against the outsideof the enclosure with a resiliency allowing easy pulling of the tabawayfrom its position against the outside of the enclosure for opening theclosure in the intended manner.

By a different aspect of this invention, in a preferred form thereof, abag is provided having a closure formed between two walls and a tabformed unitarily with at least one of the walls and lying outside of theclosure. The tab has an entrance edge that is disposed at substantiallya right angle to the outside edge of the seal adjacent to it.

By an aspect of this invention the bag is made from a sleeve ofthermoplastic film stretch oriented about 4:1 to 25:1 biaxaially. Thebottom of the bag is formed by sealing the walls of the collapsed sleevetogether along an are extending across the walls of the collapsedsleeve. The sleeve is of uniform circumference, therefore, the sideedges of the bag are straight and extend parallel to the axis throughthe center of the bag from the opening.

A skirt is formed below the seal closing the bottom of the bag. Thisskirt extends about inch below the seal at its narrowest point. Theskirt has a tab sector that extends from one side of the sleeve to amedial region below said arc. A notch is formed in the tab sectorpassing through the side edge of the sleeve and dividing the tab sectorinto a lower tab portion and a smaller upper nub portion. The edge ofthe tab formed by the notch is directed at a right angle to the outsideedge of the seal. The top edge of the bag has a configuration that is anopposite and opposed configuration substantially parallel to theconfiguration of the bottom edge of the skirt.

By another aspect, a method is provided for using a vacuumized packagehaving plastic walls that enclose an object and a tear tab formed from apastic wall and positioned wholly outside of a seal attaching twoabutting walls together to close the package, the seal extendingsubstantially Wholly across one edge of the package and the tear tabhaving an extrance edge directed across the seal toward the object. Inuse the package is opened by pulling the tab until its entrance edgeleads it through the seal. The pull on the tab is continued until theseal substantially strips from the package substantially opening oneentire edge of the package. Then at least part of the object iswithdrawn from the package and the amount of the object is reduced tosuch an extent that the opened edges of the package may be folded overto form a closure for further storage of the remainder of the object.The remainder of the object is then replaced fully into the packageenclosure or left in the package enclosure and the opened edges of thepackage are folded over to form a closure protecting the remainder ofthe object in the package. Thus the package part of the enclosure canserve as the container for restoring leftovers.

By an aspect of the method for using a vacuumized package, when twoopposed abutting walls are held in engagement due to the vacuum and forma tight package conforming to the shape of the enclosed object, theopening of the seal releases the vacuum and allows the walls to separateeasily upon the movement of the object. The parting of the wallsincreases the volume of the enclosure.

Further aspects of the present invention will become apparenthereinafter and the specification concludes with claims particularlypointing out and distinctly claiming the subject matter which we regardas our invention. The invention, however, as to organization and methodof operation, together with other objects and advantages, may best beunderstood by reference to the following description when taken inconjunction with the accompanying drawings in which:

FIG. 1 is a plan view of one side of a bag embodying our invention;

FIG. 2 is a diagrammatic plan view of the package embodying ourinvention;

FIG. 3 is a diagrammatic perspective view of the bottom of the packageof FIG. 2 with the tab pulled out from the side of the package;

FIG. 4 is a diagrammatic perspective view showing how the tab is grippedfor the opening of the package;

FIG. 5 is a diagrammatic perspective view showing the tab and tear stripportion of the package torn away;

FIG. 6 is a diagrammatic perspective view showing how the package ispeeled open after the tab and tear strip have been removed;

FIG. 7 is a diagrammatic plan view of the bottom of a variation of thebag of FIG. 1 showing a different tab construction; and

FIG. 8 is a diagrammatic plan view similar to FIG. 2 but showing adifferent package.

Referring first to FIG. 1 of the drawings, there is shown a plastic bagor container 10 having an open top at top edge 11, a front wall 12 and aback wall 13 (see FIG. 6), side edges 14 and 15 and a sealed bottom 16.The sealed bottom has a closing means or closure seal 17 and a skirt 18along the bottom edge. The skirt 18 has a tab sector 19 which is dividedby notch 20 into a tab 21 and a nub 22. The entrance edge 23 of the tab21 extends towards the seal 17 perpendicularly to the seal. The notch,of course, also extends towards the seal perpendicularly. The skirt alsohas a front or top wall 12a and a back or bottom wall 13a which are, ofcourse, extensions of the walls 12 and 13 respectively of the bag proper(FIG. 3).

The bag 10 is preferably made by processing a single continuous unitarytubular sleeve of biaxially oriented plastic film by sequentially heatsealing or fusing across the collapsed sleeve in an arc having a regularline configuration free of abrupt changes in direction. The are shouldpreferably be the arc of a 6 to a 12 inch circle, most preferably aboutan 8 inch circle, which is the one represented at 17 in FIG. 1. Afterthe bag closure is formed, the bag is severed from the sleeve by cuttingthrough the tubular sleeve below the fused seal or closure seal 17leaving a skirt portion 18 and a tab sector 19, as may also be seen inFIG. 1. A notch 20 is formed in the tab sector 19 to provide a tab 21with an entrance edge 23. It is preferred that the notch be through thefolded side edge 15a of the side wall edge of the collapsed sleeve andthat the bottom of the tab sector extend at a right angle to the sideedge 15 in the bag. The skirt should 4 preferably be A; to inch wide atits narrowest point, more preferably inch wide. In some instances it ispossible to dispense with the skirt outside of the tab itself when theseal area is sufiiciently strong by itself.

Other constructions of the bag are contemplated within the scope of ourinvention. For example, because the arc may vary and in some cases thebottom of the bag may be sealed straight across or in some otherconfiguration. The tab may be formed by cutting the film so that a tabor tab portion is left projecting beyond the sealed area. In this mannera tab of any desired width can be provided projecting beyond any regionof the seal. In fact, two or more tabs could be provided. For example,two tabs 36 and 37 could be provided below a seal 17 as shown in FIG. 7.These tabs could be pulled away from one another to form two openings.Other modifications will also suggest themselves to those skilled in theart. The preferred construction is, however, the construction shown inFIG. 1. The closure can, of course, be formed after the bagconfiguration has been cut out of the sleeve. The bag can also be formedby assembling several separate sheets of film together. However, thepreferred manner of constructing the bag is the one given first.

When the bag is to be used for packaging a perishable food such as aturkey, which has protruding parts such as the wings and legs, it ispreferable to make the bag from a thermoplastic film with balancedorientation that has a fairly high shrink tension, about 200 to 400p.s.i. in each direction at 205 F. Such a film will apply a firmconforming pressure to the packaged product when the bag is of anappropriate size in relation to the product and the amount of shrink.Generally a turkey weighing 12 pounds requires a 13 inch wide bag ofunshrunk dimension, having a preferred unrestrained shrink of 40- 45% at205 F. Such products are usually frozen during storage and therefore thepreferred film should retain its flexibility at temperatures of lessthan 0 F. and more preferably 50 F. and even -70 F. to provide goodcharacteristics when the product is quick frozen at low temperatures.The film should preferably be very resistant to tear initiation and haveeasy tear propagation. The film clarity may range from transparent toopaque, depending on customer preference. The film is frequently tintedwith a white or flesh colored pigment to give a good flesh tone to theproduct as determined by customer need. Such tinted film is generallytranslucent so that the product can be inspected. Because such packagingusually lends itself to convenient hot water shrinking, the film shouldhave good shrink performance at temperatures of about 200 to 205 F. inwater. Cross-linked polyethylene film oriented by stretching biaxiallyat a total orientation ratio of about 16-1 at 205 i.e., in thisparticular instance about 4:1 transversely and about 4:1 longitudinallyin the machine direction which provides a balanced film havingsubstantially equal orientation in both directions, transversely andlongitudinally, is a preferred film. The preferred oriented film isabout 0.0015 to 0.0030 inch thick before shrinking.

When the bag is to be used for packaging a p risha l food such as ringbologna, which has regular dimensions and is not frozen during storageit is preferable to make the bag from a thermoplastic film that has alow oxygen permeability, on the order of 200-400 cc. at 72 F. per mil offilm thickness, one square meter in size per 24 hours at atmosphericpressure. A film of lower shrink tension is appropriate and preferred,on the order of about 30-180 p.s.i. in each direction at 205 F., morepreferably about 30 to p.s.i. at 205 F. Such a film will conform well tothe packaged product when the bag is of an appropriate size and once setadequately hold the package shape. The bag should be of a size allowingeasy insertion of the product and should have sufiicient free shrink inrelation to the product to form a package free of large wrinkles whenshrunk. An unrestrained shrink of 40-45% at 205 F. has been founddesirable and is preferred. A 14 inch length of bologna weighting about1 pound typically uses a bag 7 inches wide and 12 inches deep ofunshrunk dimension having the described characteristics. Such productsare usually stored at temperatures of about 3540 F. and thus thepreferred film will retain its flexibility at least as low as about 40F. The preferred film should have good resistance to fat, grease and oiland low permeability to gases in general. The film should preferbalyalso have low water vapor permeability less than 1.0 and, morepreferably, 0.8 gram at 100 F., 100% RH. per mil of thickness onehundred square inches in size per 24 hours. The film should preferablybe very resistant to tear initiation and have at least fairly easy tearpropagation. It is preferable that the film be transparent to allowinspection of the product. Because the packaging of such food stuffs asring bologna usually lends itself to convenient hot water shrinking, thefilm should have good shrink performance at temperatures of about 200 to205 F. in water. Vinylidene chloride-vinyl chloride copolymer filmoriented by stretching biaxially at a ratio of about 16-1 at 120 F.(about 4:1 transversely and about 4:1 longitudinally in the machinedirection which provides a balanced film having substantially equalorientation in both directions) is a preferred film. The preferredoriented film is about 0.0010 0.0030 inch thick before shrinking.

The two preferred films specifically described above are balancedbiaxially oriented films. Therefore, the shrink tension and unrestrainedshrink values are substantially equal to those given both longitudinallyand transversely.

Gas permeability is determined by placing a film specimen in a sealedcell so that the film completely separates the upper and lower sectionsof the cell. The cell and contents are maintained at room temperature(73 F.- *2 F.) through the test. The top section is purged with drynitrogen overnight. Dry oxygen (or gas to be tested) is introduced intothe lower cell section and is permitted to permeate through the film fora predetermined period of time. The mixture of nitrogen and oxygen inthe top section is introduced into a Haldane-Henderson-Orsat gasanalysis apparatus. The oxygen in a sample is determined by absorptionof the oxygen. The film thickness is determined in mils with amicrometer. The transmission rate is calculated in cc. (24 hours, sq.meter, atm.). The permeability is calculated in cc (mil, 2.4 hours, sq.meter, atm.).

Shrink tension is determined by measuring the force exerted by a oneinch wide strip of film mounted between two arms of a holder; one arm ofwhich is stationary and the other is connected to an electronic straingauge. Proper calibration of the strain gauge permits calculation of theforce in pounds per square inch of cross-sectional area of the sample.

Unrestrained shrink is determined by marking a piece of test film with asquare ink stamp measuring ten centimeters on a side. After a ten secondimmersion in 205 F. water the percent of linear shrinkage is measuredWater vapor permeability is determined by placing a film specimen in asealed cell so that the film completely separates the upper and lowersections of the cell. The cell and contents are maintained at 100 F.i2F. throughout the test. The lower section of the cell is partiallyfilled with H O in order to maintain it at a relative humidity of 100%.Dry air is passed through the upper section of the cell until a measuredrelative humidity of 0% is obtained. A sensing element in this sectionof the cell permits continuous monitoring of both temperature andhumidity. When the relative humidity in the upper section of the cellreaches 0%, the cells are closed and the air flow stopped. At thispoint, the rate of increase in relative humidity in the upper section ismeasured over a narrow range at a constant temperature.

Turning now to a detailed discussion of the package of our invention,attention is directed to FIG. 2 wherein the complete package is shown ina preferred embodiment. The product shown in FIG. 2 is a 12 pound turkeyand the bag was a 13 inch wide by 22 inch interior depth, taken alongdotted line A in FIG. 1. This turkey was slipped into the bag and thebag was evacuated through a nozzle inserted into the mouth of the bag.The nozzle was connected to a vacuum pump. After evacuation the bag issealed with a metal clip 30. This procedure is done in the manner nowknown in the art. For example, as represented by U.S. Pat. 2,733,442.After the clip has sealed the mouth of the bag the bag is shrunk tautabout the turkey. The tension in the shrinking film presses filrmlyabout the turkey to hold it in a firm conformed shape. The appearance ofthe turkey is enhanced by the smooth unwrinkled plastic covering.

In FIG. 3 the tab sector may be seen pulled out showing the enlargednotch 20, and the shrunk nub 22 and tab 21. It may be seen that skirt 18has substantially drawn up against the seal 17 to form a tear strip 31.The skirt 18 shrinks up to increase its thickness and form the tearstrip 31 with the seal. The seal 17 and the shrunken skirt 1 8 each forma part of the tear strip 31. Thus both the seal and the skirt 18, in asense, form tear strips themselves. In some instances the seal 17 may beused along as a tear strip and the skirt may be dispensed with.

The tab sector 19 in shrinking draws against the side of the package inthe manner shown in FIG. 2.

The package may be better understood by a more detailed description of atypical filling and opening operation. Typically, a cooled turkey (about35 F.) is placed in the bag 10 and the bag is evacuated and closed inany manner such as by clip 30. The closed bag is then passed through ahot water shrink tunnel and passed through one or more curtains of watersprayed from both above the product and below the product. The watertemperature is usually about 205 F. and causes the film to shrink to itstaut condition on the turkey in about three to five seconds releasing aportion of the films shrink tension and orientation. Thus the packageshown in FIG. 2 is produced. When the bag is chosen for the previouslydescribed most favorable characteristics, the shrink tension of 200400p.s.i. will produce a firm, tight package. The high shrink tension willdraw the protruding parts of the turkey tightly against the body of theturkey to provide a tight package that may be easily stacked and ispleasing to the eye. Because the film is resistant to tear initiation itis unlikely to rupture during the formation of the package. The skirtshrinks the maximum amount at 205 F. lengthwise of the bag because it iswholly unrestrained in that direction. Of course, the film would shrinkeven more if subjected to temperatures above 205 F. and perhaps also ifsubjected to the same temperature for a longer period of time. The skirtis restrained widthwise and this longitudinal tension is probably theactive force causing the tab to turn against the outside of the bagwhere it will be out of the way and not exposed for accidental pullingby a customer inspecting the package. It is very advantageous that thetabs lie substantially flush against the side of the bag because thispractically eliminates the misuse of the tab to pick the package up by(-which might break the seal) or the snagging of the tab because itcaught on a projection in the display case, etc. The thickened skirt isstronger than the film in general and thus does not break or tear easilyitself. The film in the skirt is relatively or substantially unorientedor of substantially reduced orientation lengthwise of the bag because ofits unrestrained shrink in that direction as compared to its widthwiseorientation because its shrink in that direction is restrained.Generally, the more highly oriented a film is, the easier is tearpropagation in the film. Unoriented film is usually quite hard to tear.It will be noticed that the bottom edge of the skirt and, therefore, thetab is open. If this were not so the tab could form into an air bubblewhen the package was shrunk due to air trapped in a closed pocket orskirt portion.

After the package has been shrunk it is transferred to a quick freezingcompartment where the package will be quick frozen at a temperature of-6 F. for about 30 minutes. After this, the package will be transferredto a holding temperature of 0 F. or lower and maintained frozen duringshipment and after shipment until purchased by the housewife. Thepreferred package's walls, formed of the preferred bag walls, willwithstand temperatures dropping down as low as 10 F. and preferablylower, even to 40 F., with good flexibility retention. The housewifewill maintain the temperature at the freezing point until a short timebefore it is time to open the package, at which time it is preferable tothaw the package before the package is opened. However, the package doesopen satisfactorily before thawing if this is the preferred time ofopening.

After the usual procedure such as thawing, the tab 21 is pulled awayfrom the side of the enclosure 32 which encloses the turkey 33 (FIG. asshown in FIG. 4. The tab is lifted away from the side of the enclosurein the obvious manner, such as by lifting it with the finger. The tab isthen gripped as shown in FIG. 4 and the bird is held with the otherhand. The tab is pulled up and across the bottom of the package in thenatural manner. The entrance edge, which is at a right angle to theseal, will tear into and through the seal. The entrance edge of the tabdirects the tear across the seal at substantially a right angle to theseal and thereby substantially prevents failure of the tab to bringabout penetration of the seal when pulled. As the tab is pulled acrossthe package the package will tear open predominately following the tearstrip 31 across the sealed area as shown in FIG. 5.

After the tab and tear strip have been removed from the package thethumb is slipped up under the edge of the bag which has been some-whatloosened from the bird and the package is stripped back as shown in FIG.6. Tears in the film propagate easily and thus the package will tearback as the film is stripped back. Generally the film will tear backfrom the points at the edges of the opening where the tab enteredthrough the seal and at the point where the tab tore off of the packageduring opening.

Turning now to the embodiment of our invention wherein a product such asring bologna is packaged according to our invention, it is preferable touse a bag having the characteristics preferred for the product aspreviously described.

Attention should now be directed to FIG. 8. In the preferred manner ofpackaging ring bologna it is inserted into the package with the tiedends towards the mouth or top edge 11 of the bag and the bag isevacuated in the same general manner as when a turkey is being packaged.With the evacuation of the bag, the bag forms around the bologna and theopposed walls 12 and 13 of the bag go together in the region 40 withinthe circle formed by the bologna ring 41. The bag is then closed with aclip 30 as previously described and inserted into hot water as alsopreviously described in discussing the formation of the turkey package.During the shrinkdown the walls 12 and 13 will generally cling togetherin the center region 40 although it is common for the walls 12 and 13 toseparate for a short distance directly adjacent to the inside edge ofthe bologna as the film pulls taut up over the bologna. The centralportion 40, however, generally remains engaged together thus a veryattractive package is formed. The package is, in other respects, quitesimilar to the package of FIG. 2. In particular, the tab and tear stripare the same as previously described and therefore the description willnot be repeated here.

The package of FIG. 8 is opened in substantially the same manner as thepackage of FIG. 2. The tab is lifted up to the position shown in FIG. 8and then gripped as shown in FIG. 4 and torn in the manner shown in FIG.5. However, the package is generally not torn back as shown in FIG. 6but instead the bologna is gripped and pulled out of the package untilthe length of bologna desired to be cut for immediate use is exposed.This portion of bologna is cut and the remainder of the bOlOgna isstuffed back up into the package and the opening is folded shut. Thus,the package not only is easily opened but forms a package for storingthe bologna after the package has been initially opened. It should beremembered that the package is held together in region 40 only by avacuum and thus when the package is opened the walls of the bag are nolonger pressed into conformity with the sides of the bologna and awholly open bag is provided that allows easy access into its interior.

While in accordance with the patent statutes, we have described what atpresent are considered to be the preferred embodiments of our invention,it will be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from our invention,and we, therefore, aim in the following claims to cover all suchequivalent variations as fall within the true spirit and scope of thisinvention.

We claim:

.1. A package comprising a plastic container having film walls, anobject in said container, said container having a closure, said filmwalls extending beyond said closure and being informed into a tab sectorthat is free of extraneous strengthening members in its essentialfunctioning parts and is strengthened by being shruk, said tab sectorincluding a tab, said tab having an entrance edge, said entrance edgedirected to said closure.

2. The package of claim 1 wherein said closure is a seal connecting twowalls of film, and said tab lies on the other side of said seal oppositesaid object, and the entrance edge of said tab is directed across saidseal directly toward said object.

3. A package comprising a plastic container having thermoplastic filmwalls, an object in said container, said container having a fused sealclosure connecting two of said film walls, the walls of said enclosurebeing shrunk oriented plastic taut on said object, a skirt of shrunkfilm outside of said seal opposite said object, an enlarged tab sectorin said skirt, a notch in said tab sector, said notch running at a rightangle to said seal and dividing said tab sector into a tab and a nub,said tab having an entrance edge, said skirt being shrunk to substantialrelief of the tension of orientation in one direction and said tab lyingagainst the outside of said enclosure, the shrink of said skirt in theother direction both engaging the tab against the outside of saidenclosure and maintaining said tab against the outside of said enclosurewith a resiliency allowing easy pulling of said tab away from itsposition against the outside of said enclosure for opening said closure,said seal and said shrunken skirt cooperating to form a strong tearstrip.

4. The package of claim 3 wherein the enclosure is formed of a singlecontinuous unitary sleeve closed at each end, one end closed by a metalclip and the other end closed by the fused seal, said seal extendingacross said sleeve in an arc, an atmospheric vacuum within theenclosure, the tab sector of said skirt extends from one side of saidSleeve and has a bottom edge at a substantial right angle to said oneside of said sleeve, said tab sector of said skirt extending to theregion of said skirt below the medial region of said are, the notchpasses through the side edge of said sleeve, and the entrance edge ofthe tab is directed at substantially a right angle to the outside edgeof said seal when said tab is held I directly away from said enclosure.

closure from said enclosure, said skirt including a tab, said tab havingan entrance edge, said entrance edge directed to said closure.

6. The bag of claim wherein the bag is formed from shrinkabe plasticfilm and the skirt is free of extraneous strengthening members and isstrengthened by being shrunk.

7. The bag of claim 5 wherein said bag is formed from orientedthermoplastic film and said closure is in the bottom of said bag andformed by sealing two walls together, and wherein said skirt has a notchin it dividing it into the tab and a nub, the edge of said tab formed bysaid notch is the entrance edge.

8. A bag comprising walls formed of a single continuous unitary sleeveof oriented shrinkable thermoplastic film, said film oriented biaxiallyat a ratio of about 16-1, the bottom of said bag formed by a sealing ofthe walls of the collapsed sleeve together, said seal extending acrossthe walls of the collapsed sleeve in an arc of between 6-12 inches, theside edges of the bag thus formed being straight and extending along theaxis of the Opening into the bag, a skirt of film below said sealextending about to inch below said seal at the skirts narrowest point,and a tab sector of said skirt extending from one side of said sleeveand having a bottom edge at a right angle to said one side edge of saidsleeve, said tab sector of said skirt extending to the region of saidskirt below the medial region of said arc, a notch in said tab sectorpassing through the side edge of said sleeve, said notch dividing saidtab sector into a tab and a nub, the edge of said tab formed by saidnotch being an entrance edge directed at a right angle to the outsideedge of said seal and the top edge of said bag having a configurationthat is an opposite and opposed configuration substantially parallel tothe configuration of the bottom edge of said skirt.

9. The bag of claim 8 wherein said bottom seal is formed by fusing thesides across the collapsed sleeve n an 8 inch circular arc having aregular line configuration free of abrupt changes in direction, theskirt is inch wide at its narrowest point and wherein the bag isconstructed of cross-linked polyethylene that has a shrink tension ofabout 200 to 400 psi. at 205 F. with an unrestrained shrink of 4045% at205 F., said film retaining its flexibility at temperatures of less than50 F. and having good shrink performance at temperatures of about 200 to205 F. in water.

10. The bag of claim 8 wherein said bottom seal is formed by fusing thesides across the collapsed sleeve in an 8 inch circular are having aregular line configuration free of abrupt changes in direction; theskirt is 4 inch wide at its narrowest point and wherein the bag isconstructed of transparent vinylidene chloride-vinyl chloride copolymen;has a low oxygen permeability, about 200-400 cc. at 72 F. per mil offilm thickness, one square meter in size per 24 hours at atmosphericpressure; a shrink tension of about 30100 p.s.i. at 205 R; anunrestrained shrink of 40-45% at 205 R; retaining its flexibility attemperatures of about 40 F.; resistant to fat, grease and oil and havinglow permeability to gases in general; having low water vaporpermeability, less than 1.0 gram at 100 F., 100% RH. per mil ofthickness, one hundred square inches in size per 24 hours; having goodshrink performance at temperatures of about 200 to 205 F. in water.

1.1. A method of using a vacuumized package having plastic wallsenclosing an object, the package equipped with a tear tab formed from aplastic wall and positioned wholly outside of a seal attaching twoabutting walls together closing the package, the seal extendingsubstantially wholly across one edge of the package and the tear tabhaving an entrance edge directed across the seal toward the objectcomprising pulling the tab until its entrance edge leads its through theseal, continuing to pull the tab until the seal substantially stripsfrom the package substantially opening one entire edge of the package,withdrawing at least part of the object from the package and reducingthe amount of the object to such an extent that the opened edges of thepackage may be folded over to form a closure for further storage of theremainder of said object and folding the opened edges of the packageover to form a closure protecting the remainder of the object restoredin said package.

12. The method of claim 11 wherein the package was under vacuum with twoopposed abutting walls held in engagement due to the vacuum to form atight package conforming to the shape of the enclosed object and whereinthe opening of the seal releases the vacuum and allows the walls toseparate easily upon the movement of the object, the parting of thewalls increasing the volume of the enclosure.

13. A package comprising a plastic container having film walls, anobject in said container, said container having a closure sealing two ofsaid film walls together, a skirt of shrunk film outside of said closureand opposite said object, said skirt having an enlarged tab sector, anotch in said tab sector running toward said seal, one side of saidnotch forming an entrance edge, said skirt being shrunk and said tabsector lying against the outside of said enclosure with the shrink ofsaid skirt both engaging the tab against the outside of said enclosureand maintaining said tab against the outside of said enclosure with aresiliency allowing easy pulling of said tab away from its positionagainst the outside of said enclosure for opening said closure, saidseal and said shrunken skirt cooperate to form a strong tear strip.

14. The package of claim 13 wherein an atmospheric vacuum exists withinthe enclosure and said film tightly conforms to the contour of saidobject.

15. The package of claim 14 wherein center portions of two opposed wallsof film are engaged and the object forms a generally circularconfiguration around the area of the engaged wall portions.

16. A bag comprising walls formed of a single continuous unitary sleeveof biaxially oriented shrinkable plastic film, the bottom of said bagformed by a sealing of the walls of the collapsed sleeve together, theside edges of the bag thus formed being straight and extending along theaxis of the opening into the bag, a skirt of film below said seal and atab sector of said skirt extending from one side of said sleeve a notchin said tab sector passing through the side edge of said sleeve, saidnotch dividing said tab sector into a tab and a nub, the edge of Saidtab formed by said notch being an entrance edge directed toward theoutside edge of said seal.

References Cited UNITED STATES PATENTS JAMES B. MARBERT, PrimaryExaminer US. Cl. X.R. 22966 UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3: 5 ,537 Dated June 23, 1970 Inventor(s) Dreyfuset al It is certified that error appears in the above-identified patentand that said Letters Patent are hereby corrected as shown below:

Column 1 line 53 "evternal" should be --external--.

Column 8 line 30 "informed" should be --formed--.

Column 8 line 32 "shruk" should be --shrunk--.

MGNED Aih. CALEB DEC 1 11gb (SEAL) Eamammmm'l" mm 1:: =1

Offioer Domissionor 0 Patent:

FORM Pea-1050 (10-69) USCQMMDC 50376-P69 9 U S GOVERNMENY PRINTING DFHCCI969 O366334

